This invention relates to energy storage systems and devices, more particularly, to machines used for storing and transmitting energy from input sources, typically rotating shafts powered by electric or other motors, the storage and transmittal function being accomplished by means of springs.
Various systems have been long in existence which used prewound or continually rewound springs to drive an output power shaft connected to driven equipment, for example, an electrical generator. Some involve multiple units each having a spring or springs which, after being wound or released, drive gears which in turn rotate the main shaft. Others have peripheral springs around a main gear or inside a ring gear rotating on a main shaft; the peripheral springs drive small spring gears which in turn drive a larger gear secured to the main shaft.
Such a device should desirably be continually operable (assuming ample input power), speed-controllable, and have its individual spring units synchronizable to operate sequentially for the required output power and speed needs. Such desired characteristics are generally lacking in the prior art devices.
For example, in Vigneri U.S. Pat. No. 2,345,954, peripheral springs are wound individually, and a brake on the main shaft is then released. An arm mounted on the main shaft rotates a rack to rewind the springs one at a time. The disadvantages of such a system are the need for a brake while the springs are hand wound (or otherwise) in advance, and the need for spring gears to be individually wound by the rack.
In Rutzen U.S. Pat. No. 1,178,947, a ring gear rotates the spring gears, and in turn winds the springs, one at a time. In Rutzen U.S. Pat. No. 1,178,952, the ring gear has rack-like segments thereon that rotate the spring gears, and in turn wind the springs, again one at a time and sequentially. The undesirability of these systems is the need for segmental racks and spring gears.
In Rutzen U.S. Pat. No. 641,799, a main shaft rotates and turns a countershaft that winds the spring attached to the central shaft, a brake being required to prevent the central shaft from turning when the spring is rewinding; the obvious disadvantage is the need for the brake.
In Zippel U.S. Pat. No. 1,481,279, right and left springs are wound by the same motor, one at a time -- a clutch is used to connect the winding means (powered by an electric motor) to each spring winding shaft. The solenoid moves the clutch control switch on the spring to actuate the clutch. The obvious disadvantage of this system is the complicated clutching equipment.
In Joyner U.S. Pat. No. 1,776,360, peripheral springs are wound by tappets or a cam that turns the spring gears, and in turn winds the springs. The obvious disadvantage of this system is the need for the tappets or the cam, as well as the spring gears. In Joyner U.S. Pat. No. 1,833,838, multiple springs are wound by rotatable spring shafts interconnected by chains, flat spiral springs being attached to drums and shafts, the final unit being connected to an output driveshaft. The apparent disadvantage of this system is the mechanical interconnection between spring units.
In Johnston U.S. Pat. No. 487,745, flat spiral springs are employed with several clutches-- the shortcoming being the need for clutches.
Spring motors thus take on various designs, all with the objective of transmitting the power from the wound spring to an output driveshaft, some machines using prewound springs, others employing various types of rewinding mechanisms and motors. The springs used in such devices are typically of the flat spiral variety having an inner end secured to a shaft, and an outer end secured to a fixed frame member or a portion of the housing if the inner shaft is rotatable, or to a rotating drum mounted on the inner shaft if the shaft is not rotatable.
The previously described units typify those that have been made and used in the past, and evidence the apparent need for a multi-unit system wherein the spring units are optionally synchronizable or independently operable, without need for complicated rack-type spring winders or other peripheral spring gears or controllable clutches. The subject invention provides such a system.